But business has been horrible. There is simply no way she can hide that for the same price she is selling bundles half the size they were a few months ago.

"I haven't even sold a quarter of my stock," Bosibori said. "So when I go home, I cook less for the children, and I go hungry sometimes because I only eat if there's enough left over."

Places like the Kibera slum are on the front line in the global crunch over rising food prices. Half of Kenyans live on the equivalent of less than a dollar a day, and people who were already struggling to survive now find that spikes in food prices mean they must eat less—and sometimes not at all.

The slum is a telling example of what some experts call the new face of hunger—a situation in which shops and markets have plenty of food, but not enough customers who can pay for it.

Empty Stomachs

Kenyans first saw food prices rise in the wake of violence sparked by a disputed December 27 election that killed 1,200 people, destroyed thousands of shops, ruined countless businesses, and displaced at least 350,000 people from their homes. Many of these people were farmers who sold produce to their neighbors.

Since then, prices have gone up for just about everything—from kale, fish, and onions to flour, corn, cooking oil, and charcoal.

Now global food price hikes, as well as rising fuel costs, are likely to exacerbate a national economic swoon brought on by the violence. Already, Kenya's government is warning that some traders are hoarding crops in anticipation of even higher future prices.

Kibera, where tin-roofed homes sit tightly along dirt footpaths, is one of the world's largest slums. People here say they no longer eat to feel sated, but just to survive until food prices go down again. Once important dietary staples like meat, beans, and sugar are now considered luxuries.

"You have to sleep with an empty stomach, if there is nothing. All you can do is go to sleep," said Ainea Wasuka, 56, who had brought his HIV-positive niece to a clinic in Kibera.